"""Tests for the ``/healthz`` endpoint.

Kept deliberately small in Phase 0: we verify contract and shape, not
content beyond what the response model guarantees.
"""

from __future__ import annotations

from fastapi.testclient import TestClient

from app import __version__
from app.main import app


def test_healthz_returns_ok_and_version() -> None:
    """``GET /healthz`` returns 200 with status=ok and the app version.

    Also asserts ``commit_sha`` is present as a non-empty string — it
    defaults to ``"unknown"`` in dev, which still satisfies the contract
    surfaced to uptime probes.
    """
    # TestClient uses the module-level app, which has already been wired
    # by create_app() at import time — exactly the path uvicorn takes in
    # production, so the test exercises real startup behavior.
    client = TestClient(app)

    response = client.get("/healthz")

    assert response.status_code == 200, response.text
    payload = response.json()

    assert payload["status"] == "ok"
    assert payload["version"] == __version__
    assert isinstance(payload["commit_sha"], str)
    assert payload["commit_sha"], "commit_sha must be a non-empty string"